Current elevator systems include an elevator car that is controlled by an elevator controller. The elevator controller is in communication with a plurality of control panels, each of which is located on different floors of a building. The control panel includes inputs for selecting a desired floor of the building serviced by the elevator car. A signal corresponding to the selected floor is provided to the elevator controller and the elevator controller actuates the elevator drive so as to move the elevator car to the selected floor.
Current elevator systems are further configured to generate three braking profiles. One braking profile, referenced herein as an operational brake, is directed to stop the elevator car at a selected floor. Another braking profile is configured to stop the elevator car from an unintended movement, referenced herein as an unintended movement brake. As used herein, an unintended movement is the movement of the elevator car which was made without direction by the elevator controller. The third braking profile, referenced herein as a free fall brake, is configured to stop the elevator car from a free fall, which may occur if the cable is severed. The force characteristics of an unintended movement brake, free fall brake and operation brake are all different from each other. Currently, the elevator controller initiates all three braking profiles—the operational brake, unintended movement brake, and the free fall brake. The free fall brake may also be mechanically initiated, allowing the free-fall brake to operate independently from the elevator controller.
Currently, one braking system is configured to generate an unintended movement brake or an operational brake. Yet another braking system, independent of the previously mentioned braking system is configured to generate a free fall brake. Thus, it should be appreciated that the maintenance of one braking system requires the entire elevator to be shut down.
Currently, the actuation of the brake is binary, meaning the brakes are either actuated or are not. Thus, it should be appreciated that such binary systems may result in conditions of abrupt stopping or conditions where the elevator car is not level during braking.
Accordingly, it remains desirable to have an elevator system wherein all braking functions are controlled by one controller, and wherein braking forces may be distributed throughout all the braking systems so as to reduce down time for brake maintenance. It further remains desirable to have an elevator system wherein braking forces may be selectively actuated by one controller so as to prevent conditions of abrupt stopping and to provide a level elevator car during a stop.